Duplex steam-engine.



Nd; 654,759. Patented July 31,1900.

` .1. B. onoNNELL.

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N #ad www@- N0.`a54,759. f Patented July 3|, |900.

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`DUPLEX SKTEAM ENGINE.

(Application led Sept. 22, 1899.)

(No ModelJ':

3 Sheets-Sheet 3,

Nrrnn STATES" PATENT Ormea.

JonN n. onoNN'nLL, or Lnns sMMir, MIssoURr.

DUPLEX STEAM-ENGINE.

SPEGIFIGATIGN fencing page of Letters; retest No. $4,759, atea July e1, 190e.

Application und september 22,1899.' serai No. 7's1,275,-` cromati.)

`citizen 'of the United States, residing at Lees Summit, in the county of Jackson and State of Missouri, have invented a new and useful Improvement in Duplex Steam-Engines; and I declare the following to be a full, clear, and exact description of theinvention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to duplex steam-en gines; and my object is to produce an engine of the type 4havin g a'plurality of cylinders disposed end to end, duplicated onopposite sides of the machine, and operated vby a common piston-rod. 4I aim toV obtain the maximum amount oi` power at the minimum cost, this result being` edected by the repeated use of the steam and the reinforcement of partiallyexpanded steam bylive steam, thus securing a constant and equal pressure in allthe cylinders simultaneously.

My invention also relates to providing means for creating an exhaust from in front of the pistons by passing currents of live steam around the cylinders, projecting the same through contracted nozzles into steam-spaces at the outer ends of said cylinders, thereby also supplying live steam to the outer cylinders during the direct stroke and, in the preferred form of my engine, to all the cylinders during the return stroke, a system of reciprocatin g valves mounted on the piston-rod being also provided for controlling the course of the steam, deecting it to the live side'of the pistons, and excluding it, in coperation with the blastfrom said nozzles, from the exhaust side. y f p 1 g A In the accompanying drawings,\-Figure 1 represents a side elevation of an engine constructed in accordance with my invention. Fig. 2 is an enlarged vertical longitudinal section of one half of the same, the other half being an elevation. Fig. 3 is a vertical longitudinal section of a modied form, showing both ends of lthe machine. section taken on the line IV IV of Fig. 3. Fig. 5 is across-section-takenon the V4line V V of Fig. 3. Fig.` 6 isa cross-section taken on the-line VI VI of Fig. 3. Fig.'7 is a detached view of one of thevslidc-Valve bars controlling Fig. 4 is a crossthe radial ports leading from steam-cui trancesof the cylinders. I In constructing my engine Iemploy a cen- .portion with a steam-chest 2, having a port 5:, leading to a central admission-chamber 3a. Said steam-chest is also provided at its opposite ends Vwith stuiiung-boxes 4 and closed by a removable top plate 5, bored and threaded primary cylinders 10 10,'in which the-pistons 4:0 40 operate. Said cylinders alsocommuand the walls of said cylinders 10 1U also have a series of small right-angled passages 12 122", adording .communication between said cylinders 10 l0 and chambers 1111, respectively. 1313a indicate inwardly-projecting annular flanges formed integral with the Walls of the cylinders between chambers 10 10iL and 11 11a.' Castings 8 8a are also provided with a series of radial steam-ports 14 14?, communieating at their inner ends withl the tubular opening through bosses'9 9a and at their oppo-` site ends with longitudinal steam-passages 15 15, enlarged at their outer ends and tted withtubes 16163, terminating in nozzles 17 17a within the enlarged portions of passages 15 15E",` As shown in Fig. 2, means are provided vfor admitting live steam into the tubes 1,6 direct from the adjoining admission-chamber `3a during Ithe return stroke of thepistons Without passing it through the radial passages 14 145. For this purpo'sea series of openings is provided between the steam entrance 3a and passages 15 15%in which openings yare pivotally-mounted valves 553, having projecting spring-pressed arms' extending into the path of the central sliding disk 46. Also insaid Fig. `2 two sets of steampipes and nozzles are shown instead of one in each of the passages 15 15a, the operation of which will be described. Chambers 1l 11a are also provided with a series of radiallytially-located casting' 1, provided at its 'upper to receive the induction-pipe 6, through which` nicate with larger circular chambers 11 11, p

9 9m, of` small bore, communicating with the IOO 'inders 10 1()a and steam-spaces 11 11a.

extending ports 18H18, leading from saidchambers tothe enlarged portions of pas,

sage-Ways'lla. Said ports 18 18a are'equal in number to the nozzles 17 1'7a,'and are approximately at right angles to and in the. same radial planes with said nozzles, the lat. ter projecting outward slightly beyond thel orifices of said ports, and being so related thereto that a blast of steam. issuing from said nozzles will p roduce a suction or exhaust outwardly through said ports from cyl- Castings 8 8a terminate at their outer ends in bosses 19 19, bored :to provide passage for..

the rod and communication between chambers 11 11a and chambers 2O 20, formed in the adjoiningv castings 21 21, attached end- Wise to castings 8 8a by screw-threads. Cast- :ings 21 21 are 'larger in diameter than 8 8a with said chambers by means of right-angled passage-.ways 27 27a.

and contain steain-chambers of .greater cav pacity. g 22.22avdesignate projectingbosses or shoul ders, bored to provide passage for the rod and to providein the steamspace around the 4 rod `communication with the secondary cylinders '23 '23, provided at their opposite ends with annular 'anges 24 24a., formed vintegral with the walls of the cylinders. Said cylin-v ders y:also communicate endwise with chambers`2525of larger diameter through lopenings-26 .26, and .have further communication 2,8 28a indicate radial passage-Aways, a-series of which extend from the tubular boresof bosses 2.2 22aV and communicate at their outer ends with longitudinal passage-ways 29 29, enlarged :at their further ends, where they terminateat the ends of the castings. As

showninpFig. '2, said passage-Ways 2 9 29a `are j 3 said nozzles 58 are omitted. Said passage'- V6ol 4through said. ports .from the steam-spaces Ways V29 29a are yprovided with tightly-fitting tubes 3.0 30, terminating at their outer ends in nozzles Y31 31a, which project into the enlarged terminals of passage-ways .2,9 29a. 3.2 32are radiallyextendin g lports leading from chambers 25 25 to the enlarged terminals of passage-.ways 30 30a.. Saidports32 32aL have thefsame position relatively to nozzles 31 31a that ports 18 18a have to nozzles 17 17, as before 1-descri'bed, the object in both cases being, in part, to effect by means of a blast of steam fromsaid nozzles an exhaust action with which ,theycommunicate -Castings 21 21a. terminate in bosses or shoulders33 33a., bored to provide passage for the` rod and also in the space around the rodcom` muznication between chambers 25 25 and ci r of steam.` Said piston-heads consist of conical-shaped parts 42 42a 43 43, rigidly secured to the piston-rod and othenannular-members 44 44a 45 45, which are loosely mounted upon the conical parts, conicalreces'ses in the rings fitting the surfaces of said parts.

Slidably mounted on the piston-rod within the admission-chamber 3 and steam-spaces 20 2Oa and 34 34a are a series of tappet-valves 46, 47 47a, and 48 48a., which alternately open and close the tubular openings leading to` and from the adjacent cylinders. Each ofsaid valves consists of a tubular sleeve portion mounted Slidably on the rod andacircular disk portion preferably integral with the sleeveand extending outward radially therefromsomewhat beyond the openings lead-ing to or from the-cylinders or steam-spaces. VThe sleeves of these valves` extend into theadjacentcylinders and steamf'spaces far enough to contact Withthe piston-heads at the end of their strokes, either forward or return., and so make the disks alternately open andl close the entrances of the cylinders andcontrolthe direction of the steam.

'The admission of Asteam to radial passages 14 14a 28 28 is controlled by slide-valves 49 49550 50a, Figs. iand`7. Said valves consist of a series of flat bars, rectangular kin crosssection, slidab'ly mountedin correspondinglyshaped longitudinal.passagesinthe shoulders of the castings Vnear to and parallel with the rod and crossing the radial steam-passages 14 14 28 28a. Said bars or valvesare provided each with twocircular openings, one, 62, of the full sizeof the radial passages which they cross, so as to register therewith, rand the other, 63, of lesser size, so as to partially-close 'said passages. Said longitudinal passages extend through the castings from the respective cylinders to the adjoining steam-cham bers. These bars are projected `alternately into the cylinders and said chambers, being actuated in one direction by contact with the piston-heads on kthe return stroke and in the other Vbycontact with the tappet-disks on the outward stroke. Said slidebars fand the openings therein are rso arranged that 'the small openings 1,63 therein will register ywith the radial passages14 28, &c., during the direct'stroke yand the larger openings 62 during the return stroke, as hereinafter exe plained.

51 indicates bifurcated arms which straddle IOS) IIO

' the bosses on the adjacent 4ends of the cylinsteam through said slots being prevented by plates 62, which surround said arms and press against the inner surfaces of the chambers.

into which the arms extend.

Y The operation is substantially as follows: As shown in Figs. 2 and 3, steam enters at port 3 and passes through the admissionchamber 3a into the cylinder 10 onV the left side in said figures. The piston moves outwardly in the cylinder until it passes the openings of the radial passages l2, through which steam from behind the head is then free to pass. When the piston-head nears the end of its stroke, the edge of the annular portion 44 thereof contacts with the flange 13, stopping the movement of said annular portion, while the conical portion being fixed on the rod continues to the end of the stroke, thus opening passage-ways between the two parts of the piston-head, through which steam passes outwardly into space 11 beyond said cylinder. Similar action occurs simultaneously in the secondary cylinder 23, the live-steam supply for said cylinder passing through the small holes in slid e-valves 49 into radial ports 14 through pipes 16 and out of nozzles 17 into chamber 2O and thence into cylinder 23. The action of the piston-head in said cylinder is the same as that in cylinder 10, the construction of the two cylinders and related parts being substantially identical. Also during the direct stroke a portion of live steam passes through the small holes in slide-valves 50, radial passages 28, tubes 30, and out of nozzles 3l into steam-space 34. The effect of the blast ot' steam from nozzles 17 and 31 is to create a strong suction out of the adjacent radial ports 18 and 32 and the 4 steam-spaces with which they communicate,

drawing ont all exhaust-steam and tending to create a vacuum and so lessening resistance to the outward stroke of the pistons. It will be noted that the tappet-valves 46 47 48 cover the outer ends of the cylinders during the direct stroke and that this condition is essential to the described action of the nozzles. `It will also be observed that all exhaust-steam forced or drawn out of the cylinders and connected steam-spaces during the direct stroke is im mediately mixed with' live steamissuing from the nozzles, thereby becoming regenerated, so that at the end of the direct stroke the steam which has passed through or around the cylinders has almost its original expansive force. As the pistons in cylinders 10 23 near the end of their direct stroke they contact with the sleeves of the tappet-valves 47 48 and move them over, so as to close the exhaust 37 and the inner end of cylinder 23 and uncover the outer ends of cylinders 10 23. The inner end ot' cylinder l0 is covered in a similar manner by valve 46 being moved over against it by the return stroke of the piston in cylinder 10Zt on the opposite side of the engine. The return stroke in the engine as constructed in Fig. 3 is effected by the live steam which has been passed aroundA the pistons through the radial passages 14 28,n

tubes 16 30, rbc., and mixed with partiallyexpanded steam in the steam-spaces beyond the cylinders. Under my construction this steam has sufticient expansive force to eect the return stroke without aid from the direct stroke on the other side of the engine. As shown -in Fig. 2, however, live steam is supplied to the cylinders and spaces beyond them during the return as well as the direct stroke through the valves 55, nozzles 58, &c., making the pressure during the back stroke equal to that, in the forward stroke. This is true as to all the cylinders. Said valves 55 are opened for the admission of steam by contact of the sliding tappet-valve'disk 46, which is moved over at the end of the direct stroke on that'side of the engine. At the beginning of the return stroke the two parts of the pistonheads are iirst forced together, closing the passages between them. As the heads near the end of the return stroke they actuate the slide-valve bars 50, making their small holes register with the radial passages 14 28, &c., ready for the entrance of steam on the next stroke. Theyalso actuate the tappet-valves 46 47, dac., moving them over to cover the entrances to the opposite cylinders. These valves also are affected by the suction of the nozzles 17 31 57 58, which would throw the `disks over without the contact with the piston-heads, but the latter insures uniformity of action. During the return stroke in the construction shown in Fig. 2 live steam is continually passing through nozzles 57, tubes 16, and nozzles 17, 58, and 3l and acting on the outer side of the pistons. Nozzles 17 and 31 have no exhaust action during the return stroke for the reason that the outer ends of cylinders l() 23 are not at that time covered by the tappet-valves 47 48; but nozzles 57 5S, Fig. 2, have exhaust action at this time withdrawing exhaust-steam,&c. ,from in front of the returning pistons through radial passages 14 28, dac.

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y during the return stroke. .Such valves would @ij I. v 54,

to permit exhaust-steam from Vthe cylinders to'pass out through said passages; It desired",.the nozzles 58' may loeiittedv with valves 55 inthe same manner as nozzles^57, so that no steam will pass through nozzlesv 58 except beoperated by thetappet-disls 47, as will be readily understood. While a small portion of live steam mixed with exhaust passesout of exhaustport's 37 37a during each direct'v stroke, the arnonntithus lost is'not snlicient toV impair the efficiencyl of the engine, the amount of` steam allowedI to pass thro-ugh radial ports 28 28a not being over oneper cent. It is of course understood that the parts duplicated at Vthe opposite end of the engine actv alternately with those described.

Theouter ends of the piston-rod ar'e secured to cross-heads 59, attached to connecting-rods 60' andywheels 61 in the `usuall manner.

' My. engine is to be distinguished' fromthe kordinary type of compound engines-inl which steam is=first used under high pressure inaf small cylinder and afterward used e-X'pansi-vely ina larger'cylinder. In my machine the steamis=used-expansively, but only after being'mixed With'liVe-steam admitted to the inner steam-spaces through the longitudinal passages; surrounding the cylinders', so that an equality of pressure is preserved during the direct and` return strokes W-ithouft'r'eference t'o thec'ompara'tive size of the cylinders.-

. While duplicate sets of cylinders are shown, itis obvious that said cylinders maybe ar-l rangedin any multiple desired. Onthe other .hand`,.the` engine would still beoperative if all outer cylinders were removed, leaving only thel primary cylindersv l() 1O'withfrhe end caps 36'36afreduced in size, attacheddi-l rectly to them Ilclaimas my invention and desiretoseV` cureby Letters PatentV w1. Inarduplex enginefhavvingia'pair of cyl inde'rs` disposed end to end and: operated alternately by afcommon piston-rod,-an'dl pistonson said rod,asteamentrance, a central admission-chamber into which bothc'ylind'ers open, .two outer steam-chambers in the-casing? beyond'eachof" said cylinders andopeningf l into each other centrally, radial ports'for e'X-1 haast-steam leading from said cylinder'sto* the'rstzof said outer steam-chambers, radial ports-leadinglfrom the-entrances of saidic'ylf" inders, longitudinal passages con'ne'c'tingwith'I said radialv ports and leading into the second outer steam chamber, reciprocating slidevalves mounted inthe casings, transverse tosaidradial ports-and having' openings registering therewith, n'oz'zles'in therouter ends of saidv longitudinali' passages, radial ports'leading from the'first outer steam-chamber and opening into saidlongit'udinal passages immediately behind the orices of said nozzles, tappet-valves slidablylmounted onthe piston-rod, and extending radially therefrom, within said central steam-chamber and the ksecond outer stea-mchambers, and adapted Vtoalternately open and close the entrances .to the cylinders and the openings-'connecting said outer chambers,`and exhaust-ports in said second outer cham bers; substantially as set forth.

2.l In a duplex steam-engine, the combination of apair of cylindersfdisposed end to end, vvopen at their outer ends and operatedby a commonT piston-rod, divisible pistons `on said l rod, consisting of conical portions, flxedto the rod, and annularv portions surrounding said i conical portions-1 and separable therefrom, inwardly-projecting anges at the head ends of l the cylinders',against which said annular porL 5 tions'im pin ge, to 'divide the piston-head at the end of thefdi'reet stroke, a steam-entrance, a 1l central admission-chamber into4 which both cylinders open, two outer steam-chambers in the casing', Vbeyond each ofr said cylinders, l opening'into each other centrally,radial ports leading'from the entrances of said cylinders, 'longitudinal passages connecting with said 1. radial ports andleading into the secondf'outer steam-chambers, reci procating. slide valves mounted in. the casings transverse to said lradi'al ports and havingl openings registering therewith,nozzlesinlthe outer ends of said Ilongitudinal passages, radial ports leading :from the first outer steam-chamber andopen'l ying-into said longitudinal passages immedif ately'behind' the orifices of saidl nozzles, .tappetvalves`1 slidably mountedy on theV pistonrodand extending radially therefrom, within saidfc'entral steam-chamber and the second ,nately open and close the entrances to the .cylinders andi the openings connecting said *outerfchamberd and exhaust-ports in said? second outer chambers,vsubstantially asset .'forthg 3. lnHafdu'ple-X engine thecolnbinationof a -pair of cylindersfdisposed. end to end, and operated by a common piston-rod`,pistons on said rod, a central admission-chamber be- -Ktween' said cylinders and connecting there` with, two outersteam-chambers at` the head of each cylinder, communicating with each other by central openings through which the -rod passes, exhaust-ports inthe outermost of said chambers, means for passingfexpanded steamaronndor through the pistons `into the first ofsaid outer chambers at lthe end of the directstroke, tappeti-valves slidably mounted outer steamlchambermandadapted to alter-l IOO IIO

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the second outer chamber, adapted to alter'- .nately open and close the entrances to the tion of a pair of cylinders axially in line, open at both ends and operated by a common piston-rod, pistons on said rod, a central admission-chamber between said cylinders and connecting therewith,two ou ter steam-chambers, concentric with the rod, at the head of each cylinder, and connecting with each other by central openings through which the rod passes, exhaust-ports in the outermost chambers, means for passing expanded steam around or through the pistons at the end of the direct stroke, tappet -valves slidably mounted on the rod within the admissionchamber and the second outer chambers, adapted to alternately open and close the entrances to the cylinders and the openings b etween said outer chambers, radial ports leading from said entrances and connecting with longitudinal passages opening into said outer chambers, slide-valves reciprocating transversely across said radial ports and having openings registering therewith to regulate the admission of steam to said ports, openings in the inner walls of the cylinder-casings, between the admission-chamber and said longitudinal passages, in alinement with said passages, nozzles iitted in said openings and projecting into said passages beyond said radial ports, valves for admitting steam to said nozzles and means for opening said valves during the return stroke, other nozzles in the outer ends of said longitudinal passages, radial ports opening from the rst ou ter steamchambers into said longitudinal passages, behind the orifices of said last-mentioned nozzles, whereby live steam is supplied to the cylinders during the return stroke, and eX- panded steam drawn out of thepath of the pistons during4 both the return and direct strokes, substantially as set forth.

5. In a duplexengine, the combination of a central steam-entrance, a central admissionchamber, a plurality of cylinders on each side said chamber, all said cylinders being arranged axially in line and operated by a common piston-rod, and having openings at each end, through which the rod passes, the outercylinders being of greater capacity than the inner cylinders, pistons on the rod in each of said cylinders, means for passing expanded steam around or through said pistons at the end of the direct stroke, two outer steamchambers in the casing, at the head end of each cylinder, connected by central openings through which the rod passes, exhaust-ports in the outermost chambers at each end of the engine, radial ports leading from the entrances of said cylinders, longitudinal passages connectingyvith said radial ports and leading into the second outer steam-chambers, nozzles in the outer ends of said longitudinal passages, radial ports leading from the first outer steam-chamber adjacent to each cylinder and opening into said longitudinal passages immediately behind the oriiices of said nozzles, tappet-valves slidably mounted on the piston-rod and extending radially therefrom ,within said admission-chamber and the second outer steam-chambers, adapted to alternately open and close the entrances to the cylinders and the openings connecting said outer chambers, substantially as set forth.

6. In a duplex exigirle, the combination of aA central steam-entrance, a central admissionchamber, a plurality of cylinders on each side said chamber, all said cylinders being arranged axially in line and operated by a common piston-rod, and having openings at each end, through which the rod passes, pistons on the rod in each of said cylinders, means for passing expanded steam around or through said pistons at the end of the direct stroke, two outer steam-chambers in the casing at the head of each cylinder, connected by central openings, through which the rod passes, exhaust-ports in the outermost of said chambers, at each end of the engine, tappet-valves slidably mounted on the rod, within the ad- IOO mission-chamber and the second outer chambers, adapted to alternatelyopen and close the entrances to the cylinders and the openings between said outer chambers, radial ports leading from said entrances and connecting with longitudinal passages opening into said outer chambers, openings in the inner walls of the cylinder-casings, in alinement with said passages, nozzles fitted in said openings and projecting into said passages beyond said radial ports, valves for admitting steam to said nozzles during the return stroke, and means for operating said valves, other Vnozzles in the outer ends of said longitudinal passages, radial ports opening from the first outer steam-chambers into saidlongitudinal passages behind the orifices of said last-mentioned nozzles, whereby live steam is supplied to the cylinders during the return stroke, andV expanded steam drawn out of the path of the pistons during both the return and direct strokes, substantially as set forth.

In testimony whereof I affix my signature in the presence of two witnesses.

Jol-1N n. onoNNELL.

Witnesses:

F. A. SPENCER, lu. L. LANGE.

IIO 

